Objective Due to the low penetration depth and the limited ablation range of 915MHz and 2450MHz microwave in the ablation of the liver,we proposed to use 433MHz microwave for ablation treatment of malignant liver tumors.The ablation effect of 433MHz microwave ablation system on liver was investigated by means of exploratory research and design of the microwave ablation antenna at 433MHz.Methods In the design of the antenna,the slot lengths were 18mm,15mm,15mm, respectively, and the slot spacing was 10mm.The temperatures of the four points with different side distances of ablation areas were recorded in real-time and this microwave antenna were evaluated effectively with the analysis of the transverse diameter and longitudinal diameter of the ablation areas.Results A gourd shaped ablation zone was formed with the microwave ablation antenna at the frequency of 433MHz,which could not only expand the volume of the ablation zone,but also shorten the formation time of the maximum transverse diameter.Conclusions This 433MHz microwave ablation antenna is promising for the application to the microwave hyperthermia of malignant liver tumor,which provides an important reference for the conformal microwave ablation method on the new frequency band.